That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information
Please see Part I of this article and the short entry titled “Miscellaneous Notes” for information on natural history.
As mentioned in Part I of this article, snapping turtles are held in great regard as pets in places where they are not native. This is not surprising – they are hardy and interesting, and grow into impressively large animals. They are, however, not for everyone, and careful consideration should be give before acquiring a snapping turtle or its much larger cousin, the alligator snapping turtle. Hatchlings are irresistibly cute, but growing animals require a great deal of space, strong filtration systems and careful handling.
Aquarium Size and Physical Setup
Snapping turtles are entirely aquatic, rarely bask and usually leave the water only to lay eggs. Hatchlings and small turtles are best kept in water of a depth that allows them to breathe by extending their necks to the surface. They mainly walk about the bottom and are not good swimmers. If kept in deep water, they should be provided with sunken branches and rocks that provide a “highway” to the surface, lest they be weakened by the strain of swimming.
Hatchlings are invariably shy at first, and should be provided with bottom cover in the form of artificial plants under which they can hide. Nearly all become quite bold after a time – a hiding place such as a clay pot or other shelter will still be used, however.
Animals up to 10 inches or so in carapace length can be accommodated in a 55 gallon aquarium. After that point, a larger tank or outdoor pond is best. Snapping turtles can also be maintained in plastic sweater boxes and storage tubs which are dumped or drained and cleaned as needed).
Substrate complicates cleaning and is best avoided for all except hatchlings. Smooth rocks and driftwood that comes to within a few inches of the surface will allow the turtle a comfortable resting site.
Snapping turtles have disproportionately long, thick tails and can use them quite well as props while climbing. Be sure their enclosure is well covered, or too deep from which to escape. They are quite alert and will definitely take advantage of any mistakes you make in this regard.
Filtration can be a problem, especially for larger animals. Be sure to use a suitably powerful canister, submersible or pond filter. Small turtles will be stressed and unable to feed well if blown about by the filter’s outflow, so modify this by directing it upward or against a rock if necessary. Water changes, partial or full, will be required in addition to filtration.
A useful technique to help keep the tanks of “sloppy” feeders such as turtles clean is to feed the animals in a bucket or enclosure other than their home. Snappers will adjust well to this, and will often defecate after feeding if left in the feeding container for an hour or so after eating ( turtles, are, however, quite aware of their environments – some will try to escape as soon as they finish their meal, and may become stressed if left out of their tank for too long).
Light and Heat
Snapping turtles are among the most cold tolerant of the world’s turtles. I have observed them moving on the bottoms of ice-covered ponds, and basking at the water’s surface on warm days in February in NYC. Normal room temperatures are fine, and allowing them to cool slightly in winter is a good idea. They will continue to feed when temperatures are in the mid-60’s F, but less vigorously than in summer.
Snapping turtles rarely bask- when they do it is usually done in shallow water or while floating at the surface. In cool weather, an incandescent basking light will be appreciated. Unlike most turtles, snappers obtain Vitamin from their diet, and do not need a UVB source. However, such lighting more closely mimic’s the natural situation, and may provide other benefits. Therefore, I suggest using a Reptisun UVB 5.0 fluorescent bulb or a Repti-glo UVB bulb over your turtle’s enclosure.
where in nyc do they carry the monster food diet ? thats the 10 ounce can for about 6 dollars or so pellet type food for red eared sliders and other aqua turtles
Hello, Frank Indiviglio here.
Thanks for your interest in our blog.
Unfortunately I do have a local source for that product. You can order Monster Aquatic Turtle Food and related products from us online. Sorry I could not be more helpful.
Please let me know if you need any further information.
Best regards, Frank Indiviglio.
thank you frank with shipping charges its about 14 dollars? i appreciate your getting back to me i have an 18 year old female red eared slider whos more than 7 pounds when we got her she was the size of a half dollar coin her reptomin sticks go for about 14 dollars for an 11 ounce can shes a big girl lol so i figured i can mix some of the monster diet in there too ps she also eats cantaloupe an banana slices
ello Joey, Frank Indiviglio here.
Thanks for the feedback…sounds like quite a nice animal you have there, congratulations on raising her so well.
I have a few long term animals that are on expensive diets as well…I’m always reluctant to introduce changes, especially for the real old timers. Mixing in, as you mentioned, is the way to go.
Have you tried kale, romaine, bok choy, dandelion and other greens? If accepted, they are a good choice, nutritionally, and useful for “filling up” big eaters. In the wild plants constitute a large portion of the adult slider diet, so you can rely heavily upon these if she adjusts.
In my zoo days I used Mazuri and Purina turtle chows for larger animals – 4-5 nuggets would make a good meal for a slider of 7 pounds. In the past these were available only in 25 pound bags…not sure if that is still the case; might be worth looking into.
Based on our current retail and shipping, and assuming you live in New York, total cost with shipping would be approximately $15 for Monster Diet.
Please keep me posted,
Best regards, Frank Indiviglio.
Frank if i run into a problem can i email you? thank you joey btw im a young 66 year old retired construction laborer who loves animals keep up the good work
Hello Joey, Frank Indiviglio here.
Thanks for the kind words…much appreciated.
I come from a long line of construction workers in NYC as well, and have put in a good deal of time behind the shovel myself (no skill…all “donkey work” in my case!). My interests arose as did yours. My grandfather, who put in the plumbing for the Chrysler and Seagram buildings, the UN, original Yankee Stadium and many others, supplied me with skunks, flying squirrels, boas, alligators and turtles picked up at the Fulton Fish Market; my father kept a small zoo where Jacobi Hospital now stands…included there was an opossum uncovered at a construction site in the Bronx; my mother, a blood bank technician, was once called in to deal with a baboon that had arrived for use in “cleaning someone’s blood” (this before the advent of dialysis machines!).
Please email anytime (findiviglio@thatpetplace.com) and keep me posted on how your turtle fares. As I write, I’m being observed by a musk turtle that was given to me by the owner of a pet store (Survival Enterprises, across from Evander High School in the Bronx) in which I worked in 1969 – so you may have your turtle for some years to come!
Best regards, Frank Indiviglio.
Hi Frank, can you tell me how often do I have to feed my 60 cm alligator turtle and how much food ? I m afraid he gets fat and die
Thanks best regards
Hello Alfonso, Frank Indiviglio here.
Thanks for your interest in our blog. There are a few variables involved – please let me know the temperature at which the turtle is kept, diet, aquarium size and age, if known. With that information in hand I’ll be able to provide you with a more specific answer,
I look forward to hearing from you,
Best regards, Frank Indiviglio.
Hi Frank, thanks for answering me
my large alligator turtle 40 cm carapace length is placed in an aquarium 2meters long x 1m widex 80 cm h; at 80 degrees during the winter and hot in the summer period 86,90 degrees; he used to eat chicken chops with bone inside and reptivite on it 300 gr every 7 days but he is always hungry!! I’ ve been caring of my turtle for 3 years and I took him when he was 20 cm carapace length…………but now he s getting a bit fat but still growing anyway ……..
Hello Alfonso, Frank Indiviglio here.
Thanks for the feedback.
At those temps he’ll be hungry 24/7! Higher temps are good in keeping immune system going well, etc., but may result in growth problems if diet is not perfect. If possible, drop down (very gradually) to 75 F or so in winter. 90 is very warm, even in the south of their range they wouldn’t be exposed to that long-term. Not necessarily a problem, but a consideration. In northern range limits, they experience freezing temp – a breeder I know kept them outdoors in ice covered ponds…not a good risk to take, but shows limits.
Smaller more frequent meals are preferable… they are programmed to eat as much as possible, and do store fat easily and because of the reduced plastron they always appear “overweight” A good way to gauge what is normal is to check lots of photos of wild individuals – Peter Pritchard’s book, The Alligator Snapping Turtle, has many..it is also a great reference on natural history, conservation. You will need to constantly adjust, however….please pass along observations as time goes on, and we can work on a more specific schedule.
Try to base diet around whole freshwater fishes if possible…un-cleaned trout, tilapia, catfishes, (trim spines) from people food stores; if using gutted fishes be sure to continue with chickens or another source of bone. Bait fishes great, goldfish ok on occasion, not as steady diet; marine fishes fine on occasion. Crayfish also very good, hard to get in some places however.
They do take carrion, so pieces of chicken, fish ok but always try for whole animals. The huge fellow pictured here lived mainly on rats and mice ( he also passed large quantities of turtle scutes when he first arrived!) – not my preference, but he never experience hair blockages etc and bred, is very old…so whole rodents may be a good option if fishes hard to get. Some will take turtle chow, this is a good way to provide vitamins/minerals. Commercial turtle farm products likely better that pet products due to size, let me know if you need more info on that.
Good luck and please keep me posted.
Best regards, Frank Indiviglio.
Thanks Frank for the answering,
so 75 for water temperature, and one 80 gr rat 3 times a week? is it ok? or chiken chops with bones big as the head of the turtle. I do need more info on commercial food but I live in Spain and I ve never seen pellets that big that fits for my turtle………
Hello, Frank Indiviglio here.
The volume of food is reasonable – can feed 3x or break into smaller more frequent meals if you prefer. I wouldn’t go right to rats 3x week – add a mouse or 2 for awhile, build up to rats slowly. Whole animals preferable to chicken, but chicken should be kept in diet at least once weekly for now. Bones the size of its head are rough on the digestive system, better to cut if possible, but total amount of bone sounds fine. Again, they are fish specialists so if possible add to diet.
Take 2 weeks or so to lower temps, and I’d say hold at 78 for now, as it’s adjusted to warmer temps. Be sure he’s passing feces before providing large meals at the reduced temps.
I checked a bit – US zoo suppliers seem to be limiting larger turtle pellets to special orders…regular sizes too small for your needs. A turtle farm (for human consumption) closer to home, or perhaps a local zoo, might be able to help. If you use lots of fish, then no need to worry about turtle chow.
I worked with a priest from Spain at a camp near NYC many years ago…he was an expert at catching (and cooking) huge langostinos/crayfishes from the local river; these are a great food item for turtles, in case you have access to a crayfish habitat, or crayfisherman!
Good luck, enjoy and please keep me posted.
Best regards, Frank Indiviglio.
Hi Frank,
I’m following all your advices about feeding my big alligator turtle…..1 rat 80 gr every 3 days; than I decreased to 25 C the water temperature and my turtle is doing fine……….do they need some minerals or vitamins because the food is always frozen ( rat, mice, chicken meat, fish)? I read something about vit B1 deficiency or someting like that? I have a little one 13 cm carapace do I have to feed it more often??
Then I need some adiveces or a good care sheet for my mata mata a Juvinile of cm 22…………I didn’t find how often they have to eat and how much……..a feeding precise schedule………because they are prone to always eat they became obese and they die.
Thnks a lot
Hello Alfonso, Frank Indiviglio here.
Thanks for the feedback. You can feed the smaller turtle 5-6 days/week, skipping 2-3 days every so often, especially after large meals, but frequency is not so critical as less tendency to become obese at that size.
There’s a great deal of conflicting info re frozen foods, not many good studies regarding turtles. There are some problems associated with frozen marine fishes, but the work was done with penguins. We also know little about how to supplement foods for turtles, i.e. how/when to add vitamins-minerals. Your safest course of action would be to include some fresh fishes – either feeders or whole fresh water fish from a seafood market – trout, tilapia, catfish on a regular basis. In addition, use frozen food quickly – the longer it is frozen, the more nutrient loss you’ll see. A combination of fresh/frozen has proven very successful, and is a good “insurance policy”.
Re Mata-matas, here is some info I recently provided another reader – main thing is to avoid a “goldfish only” diet and vary species as much as is possible. They tend to be shy, and ;less prone to over-eating than other species; please look it over and write back to let me know if it has been helpful:
Depending on temperature, a small Mata mata can have food available most of the time – Matas seem not to overeat, in contrast to most other turtles, at least in my experience. Living in waters with such high prey densities may be a factor. I’ve seined in rivers inhabited by them – each haul contained dozens of fish species, many pet trade staples. Try to offer as many species as possible,; he may lean towards larger ones, but good to have a choice. Can use golden shiners as staple in time, pet species as treats; if you can seine local fishes that would be ideal, trim cat’s spines – walking cats, have killed caiman (not sure if they have reached your area, but natives dangerous as well).
Tong-feeding freshwater food fishes, i.e. trout, tilapia, catfish is useful, uncleaned best but cleaned ok for variety’s sake.
Gravel can pose serious problems, as they invariably swallow a good deal of it; some passes, but blockages have occurred. Wild habitat is largely mud bottomed rivers,; sand may work but still a concern. I’ve always kept them in bare bottomed/; rubberized tanks, helps in cleaning as well. Let me know if he has trouble moving about on glass, can add large river rock/shale.
Dim light preferable, UVB not necessary and barely penetrates water but not harmful. Floating plants work well in limiting light if you want it a bit brighter. Matas tend not to eat if stressed, but always good to keep aware.
I’ve not looked into pH with these guys, but am not aware of any skin problems; lower safer however. Sphagnum tends to clog filters as it breaks down, also easy to swallow. Can enclose it and peat in a muslin bag, may need quite a bit to affect pH.
an ex co-worker of mine documented “herding” behavior in large exhibits – not much on it since. He also brought to light the goldfish concerns – please see this article for more on that. The turtle I’m holding came out of a food market in, in believe, Guyana…that’s what you can look forward to, so start saving some money for an aquarium/pool!
Good luck and please keep me posted.
Best regards, Frank Indiviglio.
Thanks Frank your matamata care sheet is very helpfull for me but I’m always worried to overfeed my turtles, actually I lost one 45 cm mata and 50 cm alligator turtle of pneumonia but they were obese and a vet told me that obese turtle can die for it as it happened to me…….too bad!!…… I want to see them bigger and growing fast and they became obese……..so a 22 cm matamata small one that takes food from my hand….a lot of it…… do I have to feed it every day? How many little fish each meal? I use to give him 3 cm freshwater fishes refrozen.
Thanks best regards
Hello Alfonso, Frank Indiviglio here.
Thanks for the feedback; I applaud your diligence in seeking to provide the best for your collection.
Obesity in turtles is a real concern, but bear in mind that it usually takes decades for it to manifest as a severe health threat; I say this to ease your mind, not to downplay the threat. You’re on the right track and can take your time experimenting.
It’s very difficult to give exact recommendations, as much depends not only on factors your aware of (temperature, tank size, age) but also upon individual variations in metabolism. I’ve reviewed hundreds of feed cards assigned to animals under my care at the Bronx Zoo and am always surprised to see how many different approaches can be successfully used with the same species.
I’d say start out with 5 fish of the size you mentioned, and feed every third day (M-Th-Sun). A good way to check normal weight is to look at the underside – the mata mata’s flesh should be about even with the plastron – not bulging out, but not sunken either. Huge tanks stocked with live fish tend to keep them active and alert, with beneficial effects on weight and health (just like us!); keep that in mind when possible.
An (very!) old rule of thumb among turtle keepers was that a full meal should consist of a food item that is slightly smaller than a turtle’s head (based on average stomach size). I’ve not seen anything that verifies this, but scores of folks have used it as a good reference point without incident; using this rule, you’ll need only work on frequency as a variable…might be worth a try.
Please try to add live fish of different species when you can; you mentioned “re-frozen” if by this you mean frozen-thawed-frozen again, this is a bad idea. Best to thaw only what is needed, discard excess but do not re-freeze (this is the rule for human food, used by most zoos as well).
Good luck, enjoy and please keep me posted.
Best regards, Frank Indiviglio.
hi Frank,
I have a small alligator snapping turtle and I grew up since he was born, now it passed two years and he is like imprinted I mean he always want to eat also at low temperature and I m afraid that growing more he will break the tank because he associated me to the food. he s not scared at all.
what can I do to break this association me and the food? I tried to feed him at nite but didn’t work. I give him mouse dead fish etc
Thanks a lot
Hello Alphonso, Frank Indiviglio here.
Nice to hear from you again. There’ s nothing you can do, as far as I know, to break the association. I’ve cared for several 60-80 yr old turtles that continue to thrash about when keepers approach, even though they are fed infrequently. Most turtles are programmed to eat as much as possible, to prepare for food shortages and dormancy periods. It’s a real problem with captives, as they tend to become obese easily.
On the other hand, young alligator snappers do grow quickly, and need a lot of food. Best reared in kiddie pools or similar enclosures, as they quickly outgrow most aquariums. Chilling to 50 F or so, if possible, will send them into dormancy, but there are risks.
Re mice…many keepers use rodents, but best to rely more heavily upon fish, use mice infrequently. Whole fresh water fishes at a food market (tilapia, catfish, trout etc) may be less expensive than shiners, etc as he grows; use goldfish infrequently. Crayfishes very good if available; occ. meal of marine fish or crab, prawn fine also. Nightcrawlers as well. Some will accept turtle chows in time (keep hungry for awhile); ZuPreen makes a large nugget, suitable for adults.
Please let me know if you need any further information. Good luck, enjoy and please keep me posted.
Best regards, Frank Indiviglio.
hi Frank,
now with cool wether I don t know what to do with my alligator snapping turtle………without heater the temp drops around 15°/20° . At this temp can he eat and digest properly?
On the other hand with the heater on the temperature is around 29° and its no possible to fix it around 24° as you suggested!
What to do? I tell you for me its not possible to move the turtle outside from the big glass tank because its too big…….
thanks a lot
Hello Alphonso, Frank Indiviglio here.
Thanks for your interest the feedback. They regularly experience 15-20 C during winters in parts of the natural range; feeding should slow down a great deal. The only problem is that the immune system does not work as well at low temperatures, so there is some risk – i.e. a parasite or other condition that is kept in check by the immune system at warm temps can become serious at low temps (this is always a risk, captive or wild, during cool periods).
A smaller (lower wattage) heater than the one your using should allow you to drop the temperature a bit, but stay above 20 C…is that not an option?
Please let me know if you need any further information. Good luck, enjoy and please keep me posted.
Best regards, Frank Indiviglio.
Hello. I work at a Natural History Museum in Roseburg Oregon, and we took over the care of an adult common snapping turtle that was found in one of our local rivers about two years ago. Snapping turtles are not native to our region, and therefore cannot be released back into the wild. Our turtle Gamara weighs about 26 lbs. And is being housed indoors in a rather small enclosure which is cleaned regularly, good filtration, regular diet of whole fish-chicken liver-commercial pellets. He has had some trouble with respiratory infections and has recently been treated with antibiotic injections.
We have made him an outdoor pond which is approximately 24-39″ deep and lined with a pond liner on cement, with a small amount of land area and live vegetation. My concern is that while the pond is lovely and much larger than his current enclosure, it is not heated and there is no substrate on the bottom or any way for him to dig-in. It rarely freezes where we are, but temp does get down into the 20′ F. Should we wait until spring to put him outdoors? Do you have any suggestions regarding his housing and care that might aid in his recovery and happiness?
I would greatly appreciate your advice on this matter. Our geographic location makes it extremely difficult to find experts on snapping turtles!
Hello Kelly,
Thanks for your interest. While snappers are very cold-tolerant, and even move about below ice at times, it’s risky to overwinter them outdoors in an artificial pond. In addition to substrate, oxygen is a concern (they breathe mainly via the skin and cloaca at this time) and we don’t have any specific info as to what their actual needs are. I’ve overwintered them in deep ponds with flowing water entering, and even in cool basements where they remained active but not-feeding, but problems can arise.
Another concern is the respiratory infection…antibiotics sometimes do not kill off all of the bacteria involved, and later flare-ups can be serious. Cold temperatures depress the immune system, and even in the wild losses are highest during hibernation. I wouldn’t try with an animal that has been recently medicated, even if all else were ideal.
Best to keep him at optimal temperatures. Some individuals refuse to eat in winter, even if kept warm, but I’/m assuming yours does okay as you’ve kept him last winter.
The male common snapper pictured in this article weighs appx 75 lbs, so plan ahead! (the second photo is of a 205 lb pound alligator snapper that I kept at the Bx Zoo).
Enjoy, and please keep me posted, I’m interested to hear how treatment goes, and his appetite over the winter.
Are snappers commonly found in Oregon? I know they are widely established (one turned up in our nets in the south of Japan!) but do not have much info on your region, Thanks.
Best, Frank
I have a snapping turtle that is about 2 inches(measuring his shell only) I want to put him in a glass tank but what size should i get so he can live awhile in it before i have to get a new one?
Hi Jessica,
A 20 gallon should be good for 4 years or so, although much depends upon diet, genetics, temperature. or you can use a 10 gal for 2 years or so, and then switch to a plastic storage bin type enclosure; usually easier to manage them in light weight containers that can be dumped, rather than to filter. Best Frank
Great post, thanks for sharing! I try to read almost anyting on this topic that I can. I have been in the hobby for about 30 years, in fact I started with turtles.
Thanks for the kind words, Frank
Would 80 be to high for the water temps? And high 70s for the air?
Hi Micheal,
80 is on the high side..not likely to do any damage, but mid-70’s with a warmer spot – perhaps a bulb over 1 corner of the tank, would be preferable. Best, Frank
Okay, thank you sir.
My pleasure..let me know how all goes, Frank
Hello sir mike again, my baby common snapper arrived last week and has been feeding like crazy! Just wanted to ask you real fast, why he keeps climbing up on the driftwood. Like i said hes eating and exploring, but will occasionally climb up. Yesterday for awhile to, with his arms streched out like he was basking. Temps are around mid 70s and a bulb on one Side makin it bit warmer. Should i move him to a cooler part of the house?
Thank you so much
Hi Michael,
Temperature should be fine; I’ve noticed that certain individuals will bask, both in the wild and captivity. If the animal sems stressed, trying to leave the water continually, then high temps might be involved, but not in your case I’d say. External parasites can cause aquatic turtles to bask, but this is not common among captive snappers. Good to add a below-water shelter – broken crockery flower pot etc..just be sure it cannot become wedged inside and unnable to surface for air, Pl keep me posted, Frank
hello sir,
I just got myself a small alligator snapping turtle just 6 days ago. Its carapace length is about 9cm (3.5 inches. I set up a 10 gallon tank with submersible filtration system, UV lightning, and water heater. I kept the temperature at 26C (79F). I have not placed any decorations inside the tank.
My concern is that the turtle have not eaten ever since (been 6 days). I tried some small feeder goldfish and pellets, but it takes no interest at all. I also noticed that it closes its eyes often.
Can you help me with this? your help would be greatly appreciated.
Thank you.
Hello Alvin,
Best to raise the temperature to 82F and use dim or no lighting, at ;least until it settles in (they do not need UVB). Provide plenty of floating plastic plants as cover, along with a piece of driftwood (avail at tropical fish pet stores); they will not thrive without cover when young. Keep water at 6 inches or so. Do not disturb or handle. Avoid goldfish, as long term use has been implicated in numerous health issues in other species. Use minnows, guppies, platys, etc. Pellets should be accepted in time, but hatchlings tend to take only live fishes at first. Please let me know if you need more info, frank
Frank,
Thank you for the advise. I got one more thing that concerns me. I just realized that its eyes are a little bit white or pale, not swollen though. And my guess is that it is not eating because it often closes its eyes eyes. I have done some researches, but I have managed to find nothing about this particular eye thingy. I used anti-chlorine to ensure that the water is free from chlorine and other metals. Two questions: 1. Do you think it is because of the water? 2. Can I feed my baby alligator snapping mealworms?
I kept a red eared slider, its 20 years old, alive and well, and eats like everything from bok choy spinach shrimp fishes, pellets etc. Never have i encountered a turtle the won’t eat =(.
Thanks.
Hi Alvin,
My pleasure. All snappers have very little in common with sliders, re care, so please follow the advice mentioned earlier re diet, set-up, temps etc. Chlorine is not known to affect turtle eyes, we do not remove at the Bx Zoo. No, do not use mealworms. Eye problems etc can only be diagnosed via an experienced vet, do not rely on online research . please let me know if you need help in locating a local vet, best, Frank
Frank,
Thanks for the advice. I believe I have posted another reply here, but I am unsure on why it disappear.
I have another concern that the turtle’s eyes are turning white, its like it has white tissues on its eyeballs, the eyeballs look pale, but not swollen. I think there might be a problem with water quality because it closes its eyes most the time in the water.
So my questions are:
1. Whats with the eyes?
2. Do they really need basking spot? Because I don’t provide one, since according to my internet research they never come out of the water.
3. Are you sure that UV lightning is not needed? because I keep it indoor.
4. Are the floating cover plants the major issue that i need to fix ASAP?
5. Can I feed the turtle mealworms?
Thank you, and my apologies for asking plenty questions. I just don’t want it to die =(
Hello Alvin,
Please see earlier reply (your comments will not appear until I read and post).
They do not leave the water to bask unless troubled by external parasites, far as we know. A warmer spot with a sub-surface resting place Slightly submerged driftwood) may be utilized. They obtain Vit D3 from diet, and so do not need UVB to manufacture it in the skin. best, frank